The present invention relates, in general, to wheel assemblies and the manner of their mounting to and removal from an axle, and more particularly, relates to plastic wheel assemblies of the type used on refuse carts or the like.
The use of plastic wheels on a variety of products has dramatically increased in recent years. One area where such plastic wheels have been widely employed is on wheeled refuse or garbage carts or bins of the type commonly employed by homeowners for their trash. Typically, these carts are formed of an injection or rotationally molded plastic and have injection or blow molded plastic wheels which are mounted on the ends of a metal axle by a hub member. The wheel hub is hammered onto the end of the axle to hold the wheel in place. Removal of such plastic wheels in order to replace or repair the wheel or the cart has been difficult because the hammered hubs require special tools for their removal or essentially must be destroyed to remove them from the axle. Sometimes this process also damages the axles. Thus, more recently, wheel-mounting assemblies have been devised which snap-on to the axle or axle stub to hold the wheel to the axle.
Prior art snap-on wheel-mounting assemblies, however, have been unduly complex, visually unappealing or not well suited to the shock loading and vibration which is commonly encountered in connection with wheeled refuse carts. Moreover, the cost of prior art snap-on couplings has been undesirably high, as has their rate of failure.
Typical prior art wheel-mounting assemblies can be seen in U.S. Pat. Nos. 2,978,277, 3,907,370, 5,222,786, 5,603,555 and 5,716,107.
In U.S. Pat. No. 2,978,277 to Gaudry a two-piece hub assembly is used to secure a wheel on an axle stub. The two hub halves are forced together to simultaneously capture the head of the axle and a dove-tailed cross section of the wheel. This approach is based, in part, upon mating frictional engagement of the hub halves, but under the shock loading and high vibration which refuse carts typically experience frictional engagement of components can be unreliable. The need for multiple hub pieces and an axle with an enlarged head, also is not desirable.
The wheel-mounting assembly of U.S. Pat. No. 3,907,370 to Bard employs a mounting sleeve which is keyed to slide over the keyed end of a specially formed axle. The sleeve mates with spokes in a wheel recess and is held in place by a washer and cotter pin. An annular cap is placed over the cotter pin and washer. This approach requires axle keying, a plurality of parts and the use of tools to secure and release the cotter pin and cap.
A multiple piece hub assembly is shown in U.S. Pat. No. 5,716,107 to Parker et al. In this wheel-mounting assembly a retainer member is used to lock the wheel assembly on a groove or annular notch at the end of the axle. The hub cover is snapped into the wheel and then the wheel snapped onto the axle. Such notched or grooved axles are in wide spread use in connection with trash carts, but this assembly again requires multiple pieces and, in this case, special tools and tedious manipulation are required in order to release the resilient retainer ring fingers from the inside of the wheel so that the wheel can be removed from the axle.
Two patents which employ sleeve assemblies formed for mounting through the wheel in telescoped relation over the axle are shown in U.S. Patent Nos. 5,222,786 and 5,603,555. The device of U.S. Pat. No. 5,603,555 has a sleeve with at least one snap-acting, axle-engaging shoulder thereon which releasably retains the sleeve on the axle and at least one wheel-engaging shoulder retaining the wheel on the sleeve. As will be seen, however, both of the wheel-mounting sleeve assemblies in these patents are relatively complex and employ a plurality of pieces in order to secure the wheel on the axle.
Accordingly, it is an object of the present invention to provide a wheel assembly and wheel mounting sleeve having a minimum number of parts which can be used to mount plastic wheels, or the like, to a relatively simple grooved metal axle.
A further object of the present invention is to provide a plastic wheel assembly for a trash cart or other wheeled product which is economical to manufacture, easy to mount and to remove to enable repair or replacement of the wheel and/or the product having the wheels, is compact so as to allow its use on a wide variety of different wheeled products and is durable and capable of withstanding substantial shock loads, side-to-side shifting and vibration during normal use.
The wheel assembly and wheel mounting sleeve of the present invention have other objects and features of advantage which will become apparent from, and are set forth in more detail in, the accompanying Drawing and following Best Mode Of Carrying Out The Invention.
The wheel mounting sleeve of the present invention includes a sleeve body formed and dimensioned for mounting through a central wheel bearing bore of a wheel and formed to be telescoped over an axle. The sleeve has at least one axle-engaging shoulder releasably retaining the sleeve on the axle and at least one wheel-engaging shoulder retaining the wheel on the sleeve. The improvement in the mounting sleeve of the present invention is comprised, briefly, of the sleeve body being formed with a resilient radially displaceable, cantilevered finger carrying an axle-engaging shoulder which extends inwardly from the finger proximate an outer end of the sleeve into an annular notch in the axle, and a wheel-engaging shoulder in the form of an annular rib provided proximate an inner end of the sleeve. The sleeve body and the sleeve-receiving wheel bearing bore are also radially inwardly stepped so that the radially converging wheel spokes on the plastic wheel provide greater strength on the inside of the wheel, where axle torque stresses the wheel to a greater degree.
The present sleeve assembly can be mounted into the wheel and onto the axle without the use of tools, and a simple pointed tool can be inserted into a tool passageway through an end wall of the sleeve to remove the mounting sleeve and wheel from the axle. The tool passageway preferably is cylindrical and dimensioned to prevent use of a blade-type screwdriver and most preferably has a puncture skin thereacross to visually conceal the axle.
A wheel assembly, including a wheel and the mounting sleeve telescoped together, also is provided, as is the further assembly of the axle being telescoped inside the sleeve and wheel.